Wearable ultra-thin miniaturized mobile communications

ABSTRACT

A cellular telephone is provided with a wearable housing, desirably in a form which can be concealed in the user&#39;s clothing, wallet, or other place. The housing may be devoid of switches or buttons for controlling the cellular telephone, and control inputs can be provided through free space communications such as a short-range radio link. A module for use in portable communications devices includes chips superposed on one another on a stack, and incorporates an interposer for facilitating connections between the chips.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 12,006,053, filed Dec. 28, 2007, and claims benefit of the filingdate of U.S. Provisional Patent Application No. 60/923,478, filed Apr.13, 2007, the disclosures of which are hereby incorporated by referenceherein.

BACKGROUND OF THE INVENTION

The present invention relates to mobile communication devices such ascellular telephones, personal digital assistants (“PDAs”) and the like,and to structures useable in such devices.

Considerable effort has been devoted in the art to making mobilecommunication devices, notably, cellular telephones, smaller and thuseasier to carry. However, still further improvement would be desirable.

SUMMARY OF THE INVENTION

One aspect of the invention provides a mobile communications devicewhich includes a casing adapted to be carried unobtrusively on a user,as for example, in or under clothing worn by the user. The devicefurther includes a cellular communications circuit mounted within thecasing, the cellular communications circuit being operative to interactwith a public cellular network; and a local communications circuit, alsomounted within the casing. The local communications circuit desirably isoperative to receive information representing control inputs by freespace communication, and to send and receive information representingthe content of a message such as a cellular telephone call by free spacecommunications.

The mobile communications device also includes a control circuit mountedwithin the casing and operative to control the cellular communicationscircuit in response to signals representing control input received bythe local communications circuit.

Most preferably, the casing is in the form of a thin, flat body havingdimensions on the order of the dimensions of a standard credit card. Thecontrol circuit desirably is operative to control all of the usercontrollable operating functions of the cellular communications circuitin response to signals representing control inputs received by the localcommunications circuit. Thus, the casing can be carried in a concealedlocation, as for example, in a pocket or wallet, and the device caninteract with auxiliary input and output devices through the free spacecommunication provided by the local communications circuit. Merely byway of example, the local communications circuit may be a radiocommunications circuit, as for example, a circuit operating according tothe Bluetooth system.

In normal operation, the user need not manipulate the casing or anyinput/output devices on the casing. The casing may be entirely devoid ofinput/output devices, or have only a limited number of such devices, asfor example, only a switch for turning the power supply on and off, oronly such a switch and controls used during setup or programming.

Essentially any input/output device capable of communicating under thecommunications protocol used by the local communications circuit can beused to control the mobile communications device. For example, astandard Bluetooth keyboard can be employed.

However, a further aspect of the present invention provides an accessoryfor a mobile communications device such as a cellular telephone. Theaccessory includes a housing adapted to engage an ear of a user and awireless communications circuit mounted in the housing and adapted tocommunicate with a cellular telephone. An earphone is mechanicallymounted to the housing and is connected to the wireless communicationscircuit, whereas a microphone is also mechanically mounted to thehousing and also connected to the communications circuit. The devicealso includes an electronic camera mounted to the housing and connectedto the communications circuit. In operation, the earphone receivessignals representing a telephone call from the communications circuitand delivers sound to the user's ear; the microphone supplies audiosignals representing the user's voice to the communications circuit, andthese signals are communicated to the cellular telephone; whereas theelectronic camera supplies image signals to the communications circuit,which are also communicated to the cellular telephone. Most preferably,the housing is adapted to lie to one side of the user's head, with theearphone juxtaposed with the auditory canal of the user. The accessorycan be used with a communications device such as the cellular telephonediscussed above.

Yet another aspect of the present invention provides a module for use ina mobile communications device. The module includes a set of chips whichincorporate an application specific integrated circuit (“ASIC”), aplurality of memory chips, and an additional chip. These chips aresuperposed in a stack and electrically interconnected with one another.Most desirably, the module according to this aspect of the invention hasa height less than about 1.7 mm, horizontal dimensions less than about13 mm, and yet provides on the order of 400 module mounting terminals ormore for connecting the module to a larger circuit panel. Desirably, themodule includes an interposer having top and bottom sides which isdisposed within the stack, between two of the chips. The interposer hasupper terminals exposed at the top side and lower terminals exposed atthe bottom side. At least some of the upper terminals are electricallyconnected to at least some of the lower terminals, and the connectionsbetween at least two of the chips extend through the terminals of theinterposer.

The module desirably also includes a bottom unit substrate having a topside facing upwardly toward the interposer, a bottom side facingdownwardly away from the interposer, and top side interconnectionterminals exposed at the top side of the substrate. The bottom unitsubstrate desirably also has chip connection terminals and modulemounting terminals exposed at the bottom side of the bottom unitsubstrate. One of the chips in the stack, most preferably the ASIC, ismounted to the top side of the bottom unit substrate, whereas anotherone of the chips is mounted to the bottom side of the bottom unitsubstrate. At least some of the top side interconnection terminals ofthe bottom unit substrate are connected to the interposer. The modulemounting terminals exposed at the bottom side of the interposer are leftunoccupied so that these terminals can be used for connecting the moduleas a whole to the larger circuit panel. Most desirably, the additionalchip is provided as part of a chip scale package which has a CSPsubstrate carrying CSP terminals, the additional chips being carried onthe CSP substrate and electrically connected to the CSP terminals, theCSP terminals being bonded to the bottom side chip connection terminalsof the bottom unit substrates. The memory chips desirably are providedin association with memory chip substrates. The memory chip substratesand memory chips desirably form a part of the stack overlying the topside of the interposer. The interposer may incorporate passivecomponents such as decoupling capacitors.

These and other aspects, features and advantages of the presentinvention will be more readily apparent from the detailed descriptionset forth below, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic perspective view depicting a module inaccordance with one embodiment of the invention in conjunction with aportion of a circuit panel.

FIG. 2 is a diagrammatic elevational view of the module depicted in FIG.1.

FIG. 3 is a diagrammatic bottom perspective view of the module shown inFIGS. 1 and 2.

FIG. 4 is a diagrammatic exploded view of the module shown in FIGS. 1-3.

FIG. 5 is a diagrammatic top perspective view of the module shown inFIGS. 1-4.

FIG. 6 is a further exploded view of the module shown in FIGS. 1-5.

FIG. 7 is a diagrammatic plan view of a cellular telephone casing.

FIG. 8 is a diagrammatic elevational view of the casing shown in FIG. 7.

FIG. 9 is a functional block diagram of a cellular telephone andaccessory.

FIG. 10 is a diagrammatic perspective view of the accessory shown inFIG. 9.

FIG. 11 is a diagrammatic view of a keyboard.

DETAILED DESCRIPTION

A module according to one embodiment of the invention incorporates abottom unit substrate 20 having a bottom side 22 (FIG. 4) and a top side26 (FIG. 6). The bottom unit substrate may be a thin circuit panel, asfor example, a flexible circuit panel. The bottom unit substrate hasbottom side chip connection terminals 27 disposed in a densely packedarray in a central region of the substrate, and exposed at the bottomsurface 22. Merely by way of example, the bottom unit substrate may havemore than 100 bottom chip connection terminals, as for example, about100-200 bottom chip connection terminals 27. The bottom unit substratealso has a large number of module mounting terminals 28 disposed in aperipheral region of the substrate, and also exposed at the bottomsurface 22 of the substrate. For example, more than 400 module mountingterminals may be provided. The particular unit illustrated in FIG. 4 hasapproximately 480 module mounting terminals 28. In the particular unitillustrated, the module mounting terminals are disposed adjacent allfour edges of the bottom unit substrate 20, but other arrangements arepossible.

The bottom unit substrate 20 also has top side chip connection terminals30 exposed at its top surface 26. Only a few of the top side chipconnection terminals 30 are depicted in FIG. 6. In practice, these topside chip connection terminals are provided in a closely packed arraysimilar to the array of bottom side chip connection terminals 27,although not necessarily at the same spacings. The top side chipconnection terminals are disposed in an array in the central region ofthe substrate, close to and desirably overlying, at least in part, thearray of bottom side chip connection terminals 27. This facilitatesshort interconnections between the top side and bottom side chipconnection terminals. The bottom unit substrate 20 further has top sideinterconnection terminals 32 disposed in a peripheral region of thesubstrate, and exposed at the top surface 26. The top sideinterconnection terminals 32 typically are fewer in number than themodule mounting terminals 28, and desirably are disposed at largercenter-to-center spacings or pitch than the module interconnectionterminals 28.

An ASIC 34 overlies the top surface 26 of the bottom unit substrate 20.The ASIC has contacts bonded to the top chip connection terminals 30 ofthe bottom unit substrate. The ASIC is covered by an encapsulant 36.ASIC 34 is arranged to perform a function useful in operation of amobile communications device, as for example, base band processing orapplication processing. “Base band processing” refers to processing ofinformation constituting a message to be conveyed by the communicationsdevice, as for example, processing audio information in the case of acellular telephone. “Application processing” refers to processing ofinformation used in operation of the mobile communications deviceitself, as for example, information used to convert input datarepresenting control inputs from a user into signals to be provided toindividual components of the mobile communications device to controlthose components.

An additional chip 38, schematically depicted in broken lines in FIG. 4,is mounted to the bottom surface of the bottom unit substrate 20. In theparticular embodiment depicted, additional chip 38 is provided as partof a chip scale package or “CSP.” As used in this disclosure, the term“chip scale package” refers to an assemblage of elements incorporating achip and a package substrate having terminals electrically connected tothe chip, the substrate having an area which is less than about 1.5times, and desirably less than about 1.25 times, the area of the chipitself. The CSP substrate has terminals 42 arranged in an arraycorresponding to the array of bottom side chip connection terminals 26.The terminals 42 of the CSP are bonded to the bottom chip connectionterminals, thereby mounting the CSP and chip 38 to the bottom surface ofthe bottom unit substrate. Additional chip 38 desirably is a chip whichcooperates closely with ASIC 32. For example, the additional chip may bea Bluetooth protocol control chip, an image processing chip, a powercontrol chip, or another chip which performs application processing,base band processing, or other control or operation functions of theportable communications device.

The module further includes an interposer 44. The interposer 44 is acircuit substrate, as for example, a flexible or rigid multilayercircuit panel. The interposer has a bottom side 46 (FIG. 4) and a topside 48 (FIG. 6). Lower terminals 50 (FIG. 4) are exposed at the bottomsurface 46 of the interposer. The lower terminals 50 are depicted ascovered by masses of electrically conductive bonding materials such assolder or the like. The interposer also has upper terminals 52 exposedat the top surface 48. The upper and lower terminals are provided in theperipheral region of the interposer. At least some of the upperterminals 52 are connected to at least some of the lower terminals 50.The array of lower terminals 50 may have more terminals or fewerterminals than the array of upper terminals 52. A set of passivecomponents, which in this case incorporate discrete decouplingcapacitors 54, is also provided on the interposer. Interposer 44incorporates electrical interconnections (not shown) between the upperterminals 52 and lower terminals 48, and also connections betweencertain terminals and the passive components 54.

The module also includes a pair of DRAM units 54. Each DRAM unit 54includes a DRAM chip 56 and a DRAM substrate 58. Each of the DRAMsubstrates desirably is a thin, single-layer circuitized substratehaving a single layer of metallization on one surface. The single layerof metallization desirably includes metallic pads disposed along allfour edges. Each such pad desirably is exposed at the lower surface ofthe substrate, and is also exposed through a hole in the substrate sothat the pad is exposed at the upper surface as well. Thus, each suchpad defines an upwardly-facing terminal and a downwardly-facingterminal. The terminals of the DRAM substrates include rows of chipconnection terminals 60 extending along two opposite edges of thesubstrate, and rows of pass-through terminals 62 extending along twoother edges of the substrate. At least some of the chip connectionterminals 60 on the substrate in each unit 52 are connected to the DRAMchip 56 within that unit. Typically, the metallization layer includestraces (not shown) which extend from the chip connection terminals 60 tothe central region of the substrate, where the traces are connected tothe contacts of the DRAM chip mounted on the substrate. The connectionbetween the traces and the chip itself may be covered by an encapsulant64 (FIG. 4).

The module further includes a flash memory unit 66. The flash memoryunit 66 includes a flash memory substrate 68 and a flash memory chip 70(FIG. 6) attached to the flash memory substrate. The flash memorysubstrate 68 has rows of unit terminals 72 exposed at its bottom surfacealong two edges. These terminals 72 are disposed at locations andspacings corresponding to the locations and spacings of the pass-throughterminals 62 in the DRAM unit substrates.

As seen in FIGS. 1, 2, 3, and 4, the bottom unit substrate 20 with theASIC 34 and additional chip 38 thereon, the interposer 44, DRAM units54, and flash unit 66 are stacked in that order, with the bottom unitsubstrate 20 at the bottom of the stack, and with interposer 44 disposedbetween the ASIC 34 and the lower-most DRAM unit 54. Thus, theinterposer lies between the ASIC 34 (FIG. 6) and the DRAM and flashchips. The terminals of the various units are connected to one anotherby masses of electrically conductive bonding material. The terminals 72of the flash unit substrate and the matching pass-through terminals 62of the DRAM unit substrates are connected to one another so as to formvertical buses extending from some of the upper terminals on theinterposer 44 to the flash unit. Also, corresponding chip connectionterminals 60 of the DRAM substrates are connected to one another to formvertical buses extending upwardly from other upper terminals 52 of theinterposer 44. These vertical buses extend adjacent the periphery of thestacked memory units. The DRAM chips are disposed near the center of thestack, inside the region enclosed by the stacked terminals and verticalbuses. The lower terminals 50 (FIG. 2) of the interposer 44 areconnected to the top side interconnection terminals 32 of the bottomunit substrate 20 by relatively large solder balls provided on theterminals 50. These solder balls in the peripheral regions of theinterposer and bottom unit substrate surround the ASIC 34 andencapsulant 36 (FIG. 6).

The entire module provides a very compact structure with excellentconnectivity between the various chips in the stack. The interposerallows for rerouting of signals conveyed between those chips disposedbelow the interposer and the memory chips disposed above the interposer.Stated another way, a wide variety of connections between the ASIC 34and additional chip 38 (FIGS. 4 and 6) and the DRAM and flash chips canbe accommodated. The close coupling and numerous interconnectionsbetween the ASIC 34 and the additional chip 38 provide for rapidinterchange of data.

The module mounting terminals 26 (FIG. 4) on the bottom unit substrateare not occupied by any connections within the module itself. Thesemodule mounting terminals can be bonded by solder balls 80 (FIGS. 1 and2) to mating contact pads on a larger circuit panel 82. The moduleprovides excellent connectivity to the larger circuit panel 82. Thesolder balls or other bonding material 80 surround the chip scalepackage and additional chip 38. Because the chip scale package havingadditional chip 38 is very thin, the bottom unit substrate can bepositioned close to circuit panel 82. Thus, the solder balls 80 can besmall. This, in turn, facilitates the use of very closely spaced modulemounting terminals 28, and allows for provision of numerous modulemounting terminals and numerous interconnections to the larger circuitpanel in a small area. Only a small portion of circuit panel is shown.In practice, the circuit panel 82 has numerous interconnections andadditional electrical components mounted thereon. The additionalcomponents of a portable communications device are discussed furtherbelow. The module discussed above with reference to FIGS. 1-6 can beextremely compact. For example, the height h_(m) of the module above thetop surface of circuit panel 82 is less than about 1.7 mm, whereas thelength l_(m) of the module and width w_(m) of the module (FIG. 1) areabout 13 mm or less.

A mobile communications device in the form of a cellular telephoneaccording to a further embodiment of the invention includes a housing orcasing 84 (FIGS. 7 and 8) in the form of a generally flat, generallyrectangular body having a thickness t_(c) (FIG. 8) much less than itswidth w_(e) (FIG. 7) and length l_(c). The dimensions of the casing 84desirably are close to those of a standard credit card. Thus, the lengthl_(c) desirably is less than about 90 mm and most preferably about 85.60mm, whereas the width w_(e) desirably is less than about 65 mm and mostdesirably about 53.98 mm, and the thickness t_(c) is less than about 2mm. The cellular telephone includes a module as discussed above mountedto a circuit panel which is disposed within the casing. As will beappreciated, the compactness of the module greatly contributes to theability to accommodate the required electronic components within thecasing. As best seen in FIG. 9, the components disposed within casing 84includes a local free space communications circuit in the form of alocal radio transmitter and receiver circuit 86 with associated antenna.In the particular embodiment shown, the local radio transmitter andreceiver circuit is a Bluetooth radio circuit. The components alsoinclude a cellular communications circuit 88 adapted to communicate witha public cellular network. In the particular embodiment shown, thecellular communications circuit includes a GSM and WCDMA transceiverblock connected to an RF front end and GSM power amplifier and switch,and also connected to a WCDMA power amplifier and WCDMA duplexer. Theexact form of the cellular communications circuit, of course, will varywith the type of cellular communications circuit to be used.

The cellular telephone further includes circuitry referred to herein asa control circuit 90, which is arranged to perform functions such ascontrolling the operation of the cellular communications circuit 88,processing signals representing both message information and controlinputs, and the like. Merely by way of example, the control circuit 90is arranged to accept information representing a telephone number to bedialed, pass that information through to the cellular communicationscircuit in an appropriate format for transmission to the network, andmanage all of the numerous functions incorporated in a conventionalcellular telephone. The control circuit 90 desirably also is arranged toprocess signals representing a message, as for example, audio or videosignals, and to perform ancillary functions such as power management.The components of the control circuit desirably include some or all ofthe components physically mounted in the module, as for example, theflash memory, DRAM, ASIC and additional chip discussed above withreference to FIGS. 1-6. The control circuit 90 is arranged to receivesignals representing user-generated control inputs through the localcommunications circuit 86. Stated another way, the user can providecontrol inputs to the cellular telephone via free space communicationsto circuit 86. Most preferably, the user provides control inputs duringnormal operation to the cellular telephone only through free spacecommunications. It is unnecessary to provide the normal array ofbuttons, switches, and the like found on the housings of conventionalcellular telephones on the casing 84 (FIGS. 7 and 8). As used in thisdisclosure, the term “control inputs” includes inputs other than anon/off input, and “normal operation” excludes turning the cell phone onor off. Thus, casing 84 may be provided with an on/off switch (notshown), or other device for directly receiving user input. For example,the casing may be somewhat flexible, and a sensor may be provided todetect deliberate flexing of the casing by the user to turn the deviceon or off. “Normal operation” excludes operations required to programthe cell phone. Thus, the casing operationally may have switches orother input devices used during programming.

Essentially any input/output device which can communicate with the localcommunications circuit 86 can be used to provide user control inputs.For example, a Bluetooth-enabled keyboard 100 (FIG. 11) having an arrayof keys 102 and internal circuitry for translating key depressions bythe user into radio signals can be employed. The local communicationscircuit receives such radio signals and translates the same intoconventional representations of alphanumeric data, which serve as thecontrol signal inputs.

A conventional Bluetooth-enabled microphone can be used to provide bothvoice message data and control data. However, a preferred device oraccessory in accordance with yet another embodiment of the invention ispartially depicted in FIGS. 9 and 10. This device incorporates a housing104 adapted to engage the ear of the user. The housing 104 may begenerally of the conventional shape used for single-ear cellularheadsets. The housing 104 may include a boom or extension 106, whichprojects forwardly from the user's ear when the housing is engaged withthe ear, so that the forward end 106 of the boom will lie near to theuser's mouth. The device incorporates a microphone 108 (FIG. 9)typically mounted near the forward end of the boom, as well as anearphone 110 mounted to the housing so that the earphone will bepositioned near the user's ear canal when the device is engaged with theuser's head. The device desirably further includes an audio processingcircuit 112 and a free space communication circuit 114, such as aBluetooth radio circuit, or other circuit compatible with the localcommunications circuit 86 of the cellular telephone discussed above.

The foregoing components of the accessory may be generally similar tothose used in conventional cellular wireless headsets.

The device according to this aspect of the present invention, however,further includes an electronic camera 114 (FIG. 9). The electroniccamera desirably includes a component such as a CCD or other imagingchip adapted to sense light impinging on the chip, together with anoptical system which typically includes one or more lenses ordiffractive elements for focusing light from a scene onto the imagingchip, and may also include image processing elements. The electroniccamera is connected to the wireless communications circuit 112. As bestseen in FIG. 10, the camera module 114 is housed within housing 104 sothat the camera module has line of sight through a clear opening orwindow 116 in the housing, facing forwardly, in the same direction asthe boom 106, so that the camera looks forwardly when the housing 104 isheld on the user's ear. Of course, the particular housing shape depictedin FIG. 10 is entirely arbitrary. Integration of a camera into asingle-ear wireless headset provides a unique combination offunctionality not heretofore achieved, including the ability to providevideo representing the user's point of view without the bulk andinconvenience associated with conventional camera-equipped devices.

As discussed above, the cellular telephone can be controlled by userinputs wirelessly transmitted to the local communications circuit 86(FIG. 9). Merely by way of example, the control circuit 90 can bearranged to interpret certain voice commands as control signals, as forexample, where the user speaks the word “dial” and then, after a pause,speaks numerals. Other, more sophisticated forms of voice control can beemployed.

The embodiment discussed above provides a compact cellular telephone.Housing 84 can be carried in a concealed location on the user's body,whereas the headset or accessory 104 can be worn unobtrusively by theuser. The user can access the full functionality of the cellulartelephone without the need to manipulate tiny buttons on a miniaturekeypad. Similar advantages can be obtained in other mobile or portablecommunications devices, as for example, PDAs.

In a variant of this approach, the housing of a cellular telephone canbe configured so that it may be worn on the user's wrist or neck, like awrist watch or medallion. the same compact arrangement of components canbe used.

As numerous variations and combinations of the features discussed abovecan be utilized without departing from the present invention, theforegoing description of the preferred embodiments should be taken byway of illustration rather than by limitation of the present invention.It is therefore to be understood that numerous modifications may be madeto the illustrative embodiments and that other arrangements may bedevised without departing from the spirit and scope of the presentinvention as defined by the appended claims.

1. An accessory for a cellular telephone device comprising: (a) ahousing adapted to engage one ear of a user; (b) a wirelesscommunications circuit mounted in the housing and adapted to communicatewith a cellular telephone; (c) an earphone mechanically mounted to thehousing and connected to the communications circuit to receive ofsignals from the communications circuit and deliver sound to the userrepresenting the received signals; (d) a microphone mechanically mountedto the housing and connected to the communications circuit to supplyaudio signals representing the user's voice to the communicationscircuit; and (e) an electronic camera mounted to the housing andconnected to the communications circuit for supplying image signalsrepresenting images captured by the camera to the communicationscircuit.
 2. An accessory as claimed in claim 1 wherein the camera andearphone are mounted within the housing.
 3. An accessory as claimed inclaim 1 wherein the housing is adapted to lie along one side of theuser's head with the earphone juxtaposed with the auditory canal of theuser.
 4. A portable communications device comprising: (a) a casing inthe form of a generally flat body adapted to be carried in or underclothing worn by a user; (b) a cellular communications circuit mountedwithin the casing, the cellular communications circuit being operativeto interact with a public cellular network; (c) a local communicationcircuit mounted within the casing, the local communications circuitbeing operative to (1) receive information representing control inputsby free-space communications and (2) send and receive informationrepresenting the content of a cellular telephone call by free-spacecommunications; and (d) a control circuit mounted within the casing andoperative to control the cellular communications circuit in response tosignals representing control inputs received by the local communicationscircuit.
 5. A portable communications device as claimed in claim 4wherein the local communication circuit includes a radio transmitter anda radio receiver.
 6. A portable communications device as claimed inclaim 4 wherein the control circuit is operative to control alluser-controllable operating functions of the cellular communicationscircuit during normal operation in response to signals representingcontrol inputs received by the local communications circuit.
 7. Aportable communications device as claimed in claim 6 wherein the controlcircuit is operative to control all user-controllable operatingfunctions of the cellular communications circuit during normal operationonly in response to signals representing control inputs received by thelocal communications circuit.
 8. A portable communications device asclaimed in claim 6 wherein the casing is devoid of user-actuatablecontrol input devices other than a control input device for controllingsupply of power to the components within the casing.
 9. A portablecommunications device as claimed in claim 4 wherein the casing has alength less than about 90 mm and a width less than about 65 mm.
 10. Aportable communications device as claimed in claim 9 wherein the casingis less than about 2 mm thick.